Semiconductor wafers may include text that is imprinted near their edges. The text can include a semiconductor wafer identifier, a batch identifier and the like. This text may be read by an optical head that has text recognition capabilities. This optical head may have a relatively high resolution that facilitates optical character recognition (OCR). OCR may include translating an image of text into text.
The optical head is expected to be relatively compact and cheap. This goal can be achieved by simplifying the optical configuration of the optical head and limiting the field of view of the optical head.
Semiconductor wafers of different sizes include text that is positioned in different locations. The limited field of view of a stationary optical head is not large enough to encompass text of semiconductor wafer of different sizes.
Prior art inspection systems included fixed optical heads that having a single field of view and were tailored to read text imprinted on semiconductor wafers of a single size.
There is a growing need to provide a system and method for reading text imprinted on semiconductor wafers of different sizes.